This type of lamp is used in particular for ultraviolet (UV) irradiation in processing technology, for example for surface cleaning and activation, photolytics, ozone production, drinking water purification, metal-plating and UV curing. In this context, the term emitter or UV emitter is also conventional. If the discharge vessel has been provided with a layer of phosphor, the UV radiation is converted into light, i.e. visible electromagnetic radiation, which opens up further use possibilities.
Document EP 1 506 567 B1 has disclosed a discharge lamp with a dielectric barrier on one side which has been provided as a UV emitter for processing technology. For this purpose, the discharge vessel 2 is filled with xenon. During the gas discharge, which is preferably operated by means of a pulsed operating method as described in U.S. Pat. No. 5,604,410, so-called excimers are formed. Excimers are excited molecules, for example Xe2*, which emit electromagnetic radiation when returning to the initial, generally unbound state. In the case of Xe2*, the maximum molecular band radiation is approximately 172 nm. In order to produce the dielectric barrier discharge, a first helical electrode 23 is arranged coaxially within the tubular discharge vessel 2. Six strip-shaped outer electrodes 8a-8f are arranged parallel to one another and with a mutual distance on the outer side of the discharge vessel 2.
One disadvantage is that previous lamps can only emit a characteristic wavelength range, namely corresponding to the lamp fill used, for example xenon. If a further wavelength range is required, for example that of XeCl excimers whose radiation maximum is approximately 308 nm, a corresponding further lamp is required.